Image::pixelate get error with imagecolorat()

[emiliodeg]

The php function imagecolorat get a color from (x,y) pixel, but works with index - 1

source

while x < this->width {
            let y = 0;

            while y < this->height {
                let x1 = x + amount/2; // here x1 can be equal or great than the image width
                let y1 = y + amount/2; // here y1 can be equal or great than the image height

when x1 or y1 are equal or great throw an error

Details

• Phalcon version: 4.0.0 beta 1
• PHP Version: 7.2.14
• Operating System: nanobox 7.2
• Installation type: Compiling from source
• Zephir version (if any): 0.11.8
• Server: Apache
• Other related info (Database, table schema):

[niden]

Addressed in #14140